so, uh, maybe you already considered this, but did you know Gubble got a sequel? A Gubble 2/II where the titular alien is walking instead of flying, and it seems he has to collect fuel to be able to fly to other platforms. It's nowhere near as prominent as the first game, although I guess still a bit more prominent than "Gubble Buggy Racer". Neither of these is currently mentioned on the Gubble homepage.
http://www.mobygames.com/game/windows/gubble-2
http://web.archive.org/web/200004180...om/gubble2.htm
(that's the first revision of the page with screenshots at the bottom)
There's several playthrough videos on Youtube.
There also seems to be a
advergame version promoting Kinder Eggs, oddly enough.
I apologize if this also isn't it/you've previously considered this, but I had no idea there was a second Gubble game (or a kart spinoff) until a few hours ago, and I'm feeling a little...bewildered.